1. Field of the Invention
The instant invention relates generally to an apparatus for the rapid packing of envelopes. The instant invention provides a novel apparatus for the packing of envelopes which increases the rate at which envelopes may be packed. More specifically, the instant invention provides for an apparatus which reduces the number of operations required to pack each envelope and which also performs each operation more efficiently than previous configurations in order to increase speed. Furthermore, buffer zones are created between operations such that each operation need not be synchronized with the others thereby allowing the removal of defective envelopes from the apparatus and without interrupting a smooth continuous flow of envelopes to the subsequent operation. The packing rate of the instant apparatus is thereby increased.
2. Description of the Related Art
Prior attempts to create an envelope packing apparatus have employed complicated systems of rotating fingers, arms, pivoting packing plates and rollers. These complicated systems result in an excessive number of moving parts which raise the cost of construction and maintenance. More importantly, these complicated systems also lower the packing rate by employed unnecessary steps and creating pauses in the packing process.
A recent attempt at a high speed envelope packing apparatus which presents deficiencies typical of the prior art can be seen in U.S. Pat. No. 5,251,425 issued to Kern (""425 patent). The feeding assembly of the ""425 patent employs a rotating opening element which must open the envelope flap prior to a conveyor element having an opportunity to remove that envelope such that a delay in feeding each envelope is experienced. Furthermore, because each operation is synchronized to the others, the delays in feeding time, as well as other operations, are perpetuated throughout the packing process and thereby cause a lower packing rate. Also, the ""425 patent packing trap must move up and down in coordination with a hold down roller to accomplish packing of each envelope thereby slowing the packing operation. Lastly, the ""425 apparatus lacks a defect operation system or any manner of dealing with defective envelopes.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 4,649,691 to Buckholz (""691 patent). The ""691 patent uses complicated clamping systems to hold each envelope and stuffing material during transport. Furthermore, the timing of these clamps must be carefully calibrated to ensure proper movement of the envelopes and stuffing. Like the ""425 patent, the ""691 patent presents a synchronous operation such that delays of any single operation are perpetuated throughout the entire apparatus and cumulated with delays of other operations. The packing assembly of the ""691 patent also presents numerous changes of direction in the envelope path creating pauses and delays. Lastly, the ""691 patent provides no detection and rejection assembly to remove unopened envelopes from the apparatus.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 3,872,649 to Wimmer (""649 patent). The ""649 patent presents only a packing apparatus without the advantage of the novel and efficient feeding assembly, defect detection means, buffer stacks and exiting conveyor of the instant invention. Furthermore, the packing apparatus of the ""649 patent comprises a complex assembly of cams rollers and intermittently swinging arms which prevents the smooth and efficient operation of the instant packing assembly.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 3,423,900 to Orsinger (""900 patent). Like the ""691 apparatus, the ""900 patent requires rotating wheels which must grab each envelope or packing material. This requires complicated coordination and excess moving parts. Furthermore, the ""900 patent provides a synchronous machine such that inefficiencies are perpetuated and accumulated throughout the apparatus. The packing assembly requires a moving packing plate, a rotating envelope delivery wheel and two conveyors to insert the packing material into each envelope. Here again the problems of proper synchronization as well as the excess of moving parts present inefficiencies and higher costs of operation and maintenance.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 3,253,384 to Huck et al. (""384 patent). The ""384 patent requires a rotating suction head which must be coordinated with the opening of each envelope and the conveying wheel which then grasps the envelope from the rotating suction head. Thereafter, the ""384 patent comprises a complex system of clamps, swinging arms and numerous changes of direction for the envelopes, all of which create losses of time in the packing apparatus. Furthermore, they create higher costs of operation and maintenance.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 2,915,863 to Kummer (""863 patent). The ""863 apparatus presents similar problems of timing due to wheels and clamps employed to move envelopes, as well as pauses due to change of direction of the envelope and packing material. The ""863 patent presents further inefficiency in the packing assembly due to the pivoting required by the packing plate to remove stuffed envelopes and the resulting delay experienced between stuffing of envelopes.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 1,668,761 to Coty et al. (""761 patent). The ""761 patent presents a bag feeding apparatus which requires two distinct operations performed in series to open a bag and remove the bag from the reserve. Furthermore, as with the previously mentioned patents, the ""761 apparatus comprises a complicated system of wheels and arms which must be properly timed thereby creating higher cost of operation and maintenance.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. 1,543,842 to Gwinn et al. (""842 patent). The ""842 patent provides a vacuum feeding assembly comprising a moving suction head which must be driven from the envelope reserve to the packing area. Furthermore, each stuffed envelope must be removed from the packing plate prior to the suction head having clearance to return to the envelope reserve to grasp another envelope.
Another attempt at an envelope packing apparatus can be seen in U.S. Pat. No. Re. 24,459 to Kern which resembles the ""863 patent and presents the same inefficiencies experienced therein.
It is therefore an object of the instant invention to provide a high speed envelope packing apparatus.
It is a further object of the instant invention to provide a high speed envelope feeding assembly which does not jeopardize the integrity of the envelopes.
It is a further object of the instant invention to provide a high speed envelope packing apparatus with a minimum number of moving parts.
It is a further object of the instant invention to provide a high speed envelope packing apparatus which performs a minimum number of operations on each envelope.
It is a further object of the instant invention to provide a high speed envelope packing apparatus which eliminates the need to synchronize operation of the envelope packing assembly to the envelope feeding assembly.
It is a further object of the instant invention to provide a high speed envelope packing apparatus which comprises a monitoring system to identify and remove defects.
The above and other objects of the instant invention are accomplished by providing an envelope packing apparatus which employs a simple envelope feeding assembly which minimizes delays in feeding envelopes, a defect detection and rejection means to remove defective envelopes from the apparatus prior to reaching the packing assembly, a simple and quick envelope packing assembly and a buffer stack of envelopes between the feeding assembly and packing assembly. The deficiencies of the prior art envelope feeding assemblies are overcome in the instant invention by forcing open the flap of each envelope in the envelope reserve by means of directing forced air onto said flap while the previous envelope is still in the process of being fed from the envelope reserve. The reserve envelopes rest in an upright position wherein the flap extends downward from the top of the envelope in a flap-closed position. The reserve envelopes are further orientated such that the flap of each envelope will extend to the exposed side of that envelope when it becomes the foremost envelope in the envelope reserve. A feeding conveyor means rests in contact with a lower portion of the foremost reserve envelope in the envelope reserve such that it does not contact the flap extending from the top of that envelope. Air pressure is continually exerted on the envelope reserve means in a manner such that the flap of a second in line envelope is blown to a flap-opened position the moment the foremost envelope has been fed downward and cleared the flap of that second in line envelope. In this manner, the flap of each envelope is opened before it is available to be fed from the envelope reserve. Therefore, the time required to open each envelope flap is not a factor in the overall processing time of an envelope. Other configurations of this concept are also disclosed hereinafter.
A sensor then checks each envelope to insure that the flap has opened. Envelopes which have not opened are detected and diverted from the stream of envelopes at that point. The remaining envelopes continue onward to a buffer stack of envelopes and then to the packing apparatus. The buffer stack of envelopes allows the packing apparatus to operate independently of the output from the feeding assembly or the defect detection and rejection means. Consequently, the packing assembly need not by synchronized to the feeding assembly. Furthermore, by making the feed rate dependant upon the number of envelopes in the buffer stack, the feeding assembly can speed up to replenish envelopes ejected from the system by the defect detection and rejection means. Therefore, a smooth, continuous flow of properly opened envelopes is delivered to the packing assembly.
The deficiencies of the prior art envelope packing assembly are overcome by employing a stationary packing trap and a threading roller connected to a laterally adjacent exiting platform. The exiting platform shifts downward to allow an envelope to be staged above the threading roller and then shifts upward so that the threading roller advances the envelope such that the envelope is placed around the packing plate. The exiting platform then shifts back downward to stage another envelope while the envelope on the packing plate is packed and removed onto the top of the exiting platform. The, difficulties typically experienced in coordinating the feeding process with the packing process are overcome by positioning the buffer stack of envelopes between the feeding assembly and the packing assembly.
Lastly, as each envelope leaves the exiting platform, it is dropped into a transfer unit which ejects the envelope to a stand-up subassembly to reorient each envelope to a vertical position. The glue of each envelope is then moistened by a reservoir such that when adjacent contorted belt guides the envelope flap into contact with the envelope body, a sealed envelope is accomplished.
The instant envelope packing apparatus has a minimum of moving parts. Because the moving parts employed in the instant invention are mostly small roller and belts employed to deliver envelopes from one operation to another the process may be accomplished at high speeds. The delays experienced by prior art envelope packing configurations are eliminated by the instant apparatus, in part, because the pivoting packing plates, large rollers, wheels, swinging arms, cams and numerous redirections of the envelopes are not employed.
Numerous other advantages and features of the invention will become readily apparent from the detailed description of the preferred embodiment of the invention, from the claims, and from the accompanying drawings, in which like numerals are employed to designate like parts throughout the same.